Lens-blank setter for lens-grinding machines



W. PHILLIPS.

LENS BLANK SETTER FOR LENS GRINDING MACHINES.

APPLICATION FILED JUNE 25 IBM.

AU. on .M m g I w mm 2 M m M W. m \n v l Mm: 2- H m I, w. m N Jig h mm m. A WW m N o WILLIAM PHILLIPS, OF ROCHESTER, NEW YORK.

LENS-BLANK SETTER FOR LENS-GRINDING MACHINES.

Specification of Letters Patent.

Patented Mar. 2, 1920.

Application filed June 25, 1917. Serial No. 176,736.

To all whom it may concern.

Be it known that I, WILLIAM PHILLIPS, a citizen of the United States, and resident of Rochester, in the county of Monroe and State of New York, have invented certain new and useful Improvements in Lens- Blank Setters for Lens-Grinding Machines, of which the following is a specification.

The present invention relates to lens blank setters for lens grinding machines, and an object thereof is to provide for securing greater accuracy in the setting of the lens blanks of multifocal lenses in their holders for grinding the short focus curves. Another object of the invention is to provide a construction which can set a plurality of lens blanks on a lens grinder holder so that a curve at any desired angle may be ground, notwithstanding variations in the thicknesses and shapes of the lens blanks. Still another object of the invention is to make provision whereby the axes of short focal curves to be formed in the lens blanks may be positioned at any desired points on the blanks while permitting said points to be relatively the same on all the lenses.

To these and other ends the invention consists of certain parts and combinations of parts, all of which will be hereinafter described, the novel features being pointed out in the appended claims.

In the drawings Figurel is a plan view of an embodiment of the invention;

Fig. 2 is a vertical section through the construction shown in Fig. 1, with the parts adjusted for grinding concave lenses;

Fig. 3 is a side view of the same'embodiment with the parts adjusted for grinding plane lenses;

Fig. 4 is a side view with the parts ad justed 'for grinding convex lenses;

Fig. 5 is a section onthe line 5-5, Fig.2 and I Fig. 6 is a fragmentary view of'the bottom of the setter. v

In forming the short focus curves of bifocal or multifocal lenses it is customary to set a plurality of lens blanks in pitch upon a lens holder by means of a setter which conforms substantially to the curve to be ground on the lenses. With this method a separate setter must be provided for each curve and no provision is made whereby the distances between the lenses may be i niform, Not only is a great expense necessary to provide a number of setters corresponding to the various curves to be formed, but it is impossible to grind any two lenses alike, that is, to have the curves for the second focal points arranged with their axes positioned at the same distance on each of the lenses. As a consequence a great deal of waste is caused because two bifocal lenses must have their short focal axes positioned alike with reference to the edges of their respective lenses.

To overcome the above objections it has been suggested to mount the lens blanks upon a holder provided with rigid abutments which define the positions of the lens blanks on the holder, and then to surround the lens blanks with pitch or resin. See, for example, U. S. Patent #937 ,7 63, granted October 26, 1909 to F. Buchhop. Provision was also made in such holder for the adjustment of the rigid abutments to obtain different angles for grinding different curves. But this construction is defective in three respects: First it did not take into consideration that lens blanks are of different thicknesses and that when holding at one time a number of lenses of different thicknesses the curves formed for the short focus would be of different depths; secondly, it failed to make provision for obtaining on! the same machine, any positioning of the axis of the short focal curve with reference to the edge of the lens; and third, no provision was made for grinding the curves at any angle on a concave lens blank, a flat lens, or a convex lens blank.

According to this invention it is possible to position lenses on a lens holder employing pitch or resin so that the thicknesses of the lens blanks need not be taken into consideration while, at the same time, the axes of the short focal curves may be situated at any.

points with reference to the edges of the blanks and this so that these points will be the same on any desired number of lenses. Furthermore, one setter may be employed for positioning blanks to form curves at any angles.

Referring more particularly to the drawings where one embodiment of the invention is illustrated, 1 indicates the supports for the lens blanks, these supports preferably having a face 2 shaped to conform to that face of the lens blank on which the short focal curve is to be ground. In this instance the face 2 is concave so as conform to the convex face of a lens blank. Each support is also provided preferably with retaining devices 3 which will properly position the blank on the support but will readily permit such blank to be withdrawn by the pitch or resin of-the holder of'thegrinding machine. In this instance these retainers are in the form of-four spring fingers arranged symmetrically about each support. In this embodiment of the invention the blank supports are symmetrically arranged about a common center and are each pivotally mounted adjacent {1 at their proximate sides.

Preferably the lens blank supports are moved equal distances simultaneously about their axes. 4 andto this end each support 1 has. a link 5 pivoted thereto at 6 near its outer edge, said links 5 being pivotally connected at 7 to a common collar or ring 8 mounted to turn on a tubular base member 9'. In this base member 9 a suppolting member 10' is guided, the supporting member carrying the. blank supports 1. Mounted t'OItLlIIl' in thebase; member) is a screw 11 having ahandwheel 12 and engaging the supporting member 10 to move the latter on'the base member. It is apparent that the relative movement of the supporting member 10 and the basemember 9 will, through the links 5, cause the'blank supports 1 to' turn simultaneously on their pivots 4:, thus permitting said blank supports to be swung to a common plane, as shown in Fig. 3, or to assume any desired angle on either side of said plane.

To the end that the centers of the short focal curves may be situated at any desired points on the lens blanks, the blank supports are relativelv adjustable, this adjustment preferably taking place simultaneously in all'of'the holders at an equal amount and being preferably in directions radial to a common point' centrally of the blankholders. In this instance, this adjustment is secured by mounting each pivot 1 on a block 13' which is guided radially on a rotary carrier 14 mounted to turn on the supporting member 10', the-latter being provided with a volute rib 15 which is engaged by projections 16 on the under sides of each block 13 so that on the rotation of the carrier 14;, the blocks 13 will b'e-adjustedradially of the carrier'and shift the pivots ttoward and from the center of rotation of the carrier. Inthis way the lensblanks may be positioned by the setter at any desired distance from the center ofthe holder of the grind ing machine, in order that the optical axis of the short focal curve will be locatedat the proper distance from the edge of its lens.

With the purpose in view of indicating the angle at Which the blank supports are set, the supporting member 10 is provided with a-scale 17 with which cooperates the upper end 18 of the base 9 to act as a pointer. Such divisions of this scale may be obtained from a fine adjustment indicator comprising a pointer 19 on. the screw 11 cooperating with a dial'plate 20 surrounding the screw and also acting to hold the lattertothe base blank is convex, the holder will have a'concave face, as illustrated in the present embodiment The holders are first adjusted radially by means of the rotary carrier 14: which when turned shifts the blocks 13' on which the pivots 4 of the blankholders are mounted. This adjustment isprovided in order that the optical axes of the short focal curves may be positionedproperly' with reference to the edgesof-the lenses. After this adjustment is secured, the hand wheel 1251's turned-until the upper portion'of thebase member 6 cooperates with the desired division on the scale 17. Should a finer ad justment be desired than is provided'for in the-scale 17', this is attained by means of the finger 19 coiiperating with the dial plate 20. It is apparent that the lens blank holder 1' maybe adjusted toa common plane, as shown in Fig. 3, or to'lie at different angles on opposite sides of'the'plane, as shown in Figs.- 2 and i 4:. After the setter has been adjusted and the blanks have been applied thereto, the setter is usedto apply the blanks to the holder of the grinding machine which, as usual, is provided with pitch .or resin in which the blanks are embedded. Owing to the fact that-the blanks have their faces on which the short focal curves are to be ground cooperating with the setter, the thickness ofthe lens is immaterial, as a thick lens will be embedded in the pitch or" resin at a greater depth than athin lens, and all the faces of all the lenses to be ground will lie thesame-distance from the holder of the grinding machine. By this arrangement it is possible to grind anumber .of lenses all having the same curve with the optical axis of said curve situated at the same distance from the edge of the lens.

What I'claim as my invention and'desire to secure by Letters Patent is j 1. A setter for applying lens blanksto the holders of grinding machines comprising amain support, a plurality of blank supports, each blank support having means for positioning a blank thereon,said means being constructed to release theiblank when the latter is applied to the lens holder of the grinding machine, and means for support ing the blank supports on the main support to permit such blank supports to assume different angles with reference to a common plane.

2. A setter for applying lens blanks to the holders of lens grinding machines comprising a main support, a plurality of blank supports, means supporting the blank supports on the main support so that the blank supports may assume different angles with reference to a common plane, and means for simultaneously moving said supports through equal distances to cause the support to assume any desired angle on either side of a common plane.

3. A setter for applying lens blanks to the holders of lens grinding machines comprising a main support, a plurality of lens blank supports, and means for supporting said lens blank supports on the main support to permit said lens, blank supports to be adjusted toward and from a common center and also with reference to a common plane.

4. A setter for applying lens blanks to the holders of lens grinding machines comprising a main support, blocks movable on the main support relatively to each other toward and from a common center, and lens blank holders pivotally mounted on said blocks.

5. A structure as set forth in claim 4, com bined with means for simultaneously moving the blocks toward and from a common center.

6. A structure as set forth in claim 4:, combined with means for simultaneously moving the lens blank holders on their plvots to cause them to assume any desired angle with reference to a common plane.

7. A structure as set forth in claim 4:,COIT1 bined with means for simultaneously moving the blocks toward and from a common center, and means for simultaneously moving the lens blank holders on their pivots to cause them to assume any desired angle with reference to a common plane.

8. A setter for applying lens blanks to the holders, of lens grinding machines, comprising a main support, a plurality of lens blank holders having relative movement on said main support, and each having a face conforming to the lens blank face on which the curve is to be ground.

WILLIAM PHILLIPS. 

